The development of cuIn1-xALSe2 thin films for use in photovoltaic solar cells

The aim of the work presented in this thesis was to develop CuInSe2 (CIS) and CuIni_„Al„Se2 (CIAS) thin films for application in photovoltaic (PV) solar cells. The purpose of the addition of aluminium (Al) in CIS thin films was to modify the energy band gap of the thin films to be nearer to the optimum for PV energy conversion and to replace the less abundant element, gallium (Ga) in CuIni_,,Ga,Se2 (CIGS) solar cells. This also makes possible the production of tandem solar cells using CIAS to make the wide energy band gap top cell and the CIS to make the narrow energy band gap lower cell. The use of very thin CIS and CIAS absorber layers in solar cell structures was also investigated; the aim was to reduce the amount of indium (In) in cell production. The CIS and CIAS absorber films were prepared by a sequential two step method in which Cu-In and Cu-In-Al precursor layers were magnetron sputter deposited onto Mo-coated soda lime glass (SLG) substrates; the CIS or CIAS was then formed by heating in a selenium (Se) containing environment. Thin film solar cells were developed in the substrate configuration and had the structure Ni-Al/Indium tin oxide (ITO)/i-ZnO/CdS/CIAS/Mo/SLG. In order to achieve high efficiency solar cells it is an important to optimse the back contact molybdenum (Mo) layer, the absorber layer, the CdS buffer layer, the window layer and top contact layers. The work described in this thesis focused on the optimisation of the back contact and absorber layers. The thin films were characterised mainly using X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), secondary ion mass spectroscopy (MiniSIMS), atomic force microscopy (AFM) and using spectroscopy measurements to investigate the effect of processing conditions on the composition, crystal structure, surface morphology and the optical properties of the films. The solar cells were characterised by current-voltage (/- V) and incident photon-to-photocurrent conversion efficiency (IPCE) measurements. Both Mo single and bilayer structures were investigated. It was found that single layers had better properties than Mo bilayers. The optimisation of the Mo deposition sputtering process yielded Mo layers which had good adherence and were conformal to the glass substrates, had low resistivity (29 if .cm), were pin hole free and had good crystallinity. The influence of Cu-In precursor layers with thicknesses in the range 90-400 nm on the microstructure of the CIS thin films (thicknesses in the range 400-1600 nm) was investigated. Solar cells fabricated from the CIS films of thicknesses 500 nm and 900 nm yielded highest cell conversion efficiencies of 4.3% and 8.2%, respectively. The selenisation of the magnetron sputter deposited Cu-In-Al precursor layers was carried out at a temperature of 550°C. Films were poor in surface quality and adhesion. Films prepared from the precursor layer with n [(Al/(Al+In))] = 0.21 had a non-uniform Al depth profile towards the bottom of the film. Although the film was found to be photoactive its effective energy band gap was 0.98 eV suggesting the properties of CIS. This confirmed incomplete mixing of Al in the thin films which was considered to be segregated at the bottom of the film. The thinner layers of Cu-In-Al precursors with thicknesses in the range 0.55¬1.00 gm and n [(Al/Al+In)] in the range 0.28-0.54 were magnetron sputter deposited. The precursor layers showed the prominent binary A1Cu4 compound with a uniform distribution of Al in the layer. Thin films converted from these precursor layers of thicknesses in the range 1.3-2.0 pm were fairly uniform in surface structure. Films with x 0.2 were found to have an energy bandgap of 1.10 eV and were also photoactive. Solar cells fabricated from this absorber film yielded a highest cell efficiency of 4.9%. Environmental impact assessments have been made on materials and the processes used in the fabrication of CIS and CIAS and..

Characterisation of Thin Films CuIn1-xAlxSe2 Prepared by Selenisation of Magnetron Sputtered Metallic Precursors

Thin films of CuIn1-xAlxSe2 have been produced by the selenisation of magnetron sputtered Cu/In/Al precursor layers using elemental selenium and the chemical and physical properties of the layers have been determined for different conditions of synthesis. For optimum conditions of synthesis it was found possible to produce single phase films with the chalcopyrite structure. These films were pinhole free, had good adhesion and were conformal to the substrate. The films had uniform depth profiles as determined using the MiniSIMS. The layers were highly photoactive, indicating that they have the potential to be used to fabricate thin film photovoltaic solar cell devices

Solar Photovoltaic panels utilization to extract clean and green energy for utility application using PVsyst software: A Bibliometric Review

This paper presents a survey on educational documents in the field of solar photovoltaic (PV) utilization to extract clean and green energy. The main purpose of this bibliometric analysis is to understand the size of the available documents for the research of PV solar panel utilization using PVsyst. This detailed review was conducted in the PV research, literature considering all subjects from the Scopus database. The pattern for the specific arrangement of keywords was separated with the recovered results from the Scopus database, publication type, year of publication, distribution conveyance by nations, subject classes, association, authors, and financing organizations. It was discovered from the close examination that mainly conferences, articles, and review papers from the United States of America, India, and Spain have significant contributions in publication. The time series dataset started in 1999 till date. Major contributions are from the branches of Engineering and Energy, Material Science, Physics, and Astronomy

Solar Photovoltaic Performance Monitoring: A Bibliometric Review, Research Gaps and Opportunities

Electrical power generation has been revolutionized by growing demand and use of Renewable Energy (RE) sources such as Solar Photovoltaic (SPV) as the main electricity source in modern times. The main objective of this bibliometric analysis is to understand the scope of the literature available for SPV performance characterization. This detailed reviewed was performed on the documents related to SPV research considering all the subject categories from Scopus and Web of Science (WoS) databases. The patterns for the particular set of keywords were broke down with the recuperated outcomes from Scopus database in the language, publication type, year of publication, distribution conveyance by nations, subject classes, association, authors, financing organizations, and patents filed. The articles on SPV characterization revealed a remarkable improvement which gains importance of review paper in this research area. This research study reports some significant research gaps and shows future perspectives for research in this field

Bibliometric Review of MPPT Algorithms for Wind Energy Conversion Systems

The existing conventional fuels are going up in prices and going down in availability. This has boosted the demand for renewable resources like wind energy. Wind energy being abundantly available is becoming very popular as it is a freely available pollution-free green energy. Some technical aspects like the tracking of maximum power from the wind energy conversion systems have a very high impact on the efficiency of the wind energy conversion systems. Several algorithms have been implemented for tracking the maximum power point of the wind energy conversion systems. The main objective of this paper is to study the extent of the available research works in the domain of maximum power point tracking for wind energy conversion systems. The bibliometric analysis done in this study is primarily based on the data extracted from the Scopus database, Mendeley, and Research Gate. Open-source software Gephi was used in the study for drawing clusters. GPS visualizer is used for the geographical analysis in this study. From the bibliometric review, it can be inferred that major publications are from journals, conferences, and articles from Indian publications and followed by Chinese publications. This study is done starting from the year 2010 to 2020. It spans over a decade. The subject areas of Engineering followed by Energy, Computer Science and Mathematics have the maximum contribution in this domain

Bibliometric review of Energy Storage System for Grid connected Wind Power Plant

The integration of RESs like wind energy pose several problems for aggregators and grid operators majorly because of their intermittent and unstable behavior. The instability and intermittency can be reduced through accuracy in forecasting and reliable and effective storage and utilization. The main objective of this bibliometric review is to understand the extent of the available literature for the area of Energy Storage Systems for renewable energy resource specifically grid connected wind power plants. The bibliometric analysis is primarily based on Scopus, Research Gate, Mendeley and tools like GPS visualizer. It is revealed from the bibliometric analysis that major publications are from conference, journals and articles from Indian publications, followed by Chinese and publications from the US. The time series dataset started in 1976 till date. The major contribution is by the subject areas of Energy and Engineering followed by Environmental Science, Computer Science and Mathematics

Extraction of Photovoltaic Module Parameters from Outdoor and Converting into Standard Test Conditions

Photovoltaic (PV) technology turns to be an evolving technique worldwide. This paper describes the technique used to extract the photovoltaic module characteristics from the outdoors and then converting it to Standard Test Conditions (STC). By applying this technique, the required electrical parameters such as fill factor, maximum power, short circuit current, open circuit voltage, efficiency for the polycrystalline module are determined under the outdoor test conditions. An electronically varying load has been used to trace the current voltage characteristics of PV module. Current and voltage values from the photovoltaic module are recorded using the microcontroller board and then it is displayed on the monitor. The standard protocols are used to convert the PV raw data into Standard Test Condition (STC). Measured results are compared with STC results which are provided by the manufacturer and their difference should be targeted in the error margin (±3%) of the current voltage characteristics

Solar photovoltaic module performance characterisation using single diode modeling

Single or double diode electrical modeling of SPV module gives valuable results which will help to identify the exact behavior of SPV module under the normal operating condition. Accurate modelling of SPV module will also help to calculate internal resistances (Rs, Rsh) and parasitic of the SPV module. The main contribution of this work is the stepwise simplification of the current equation of single and double diode electrical model of SPV module. Then the single diode model of SPV module having 36 SPV cells in series is simulated in LTspice simulator. Simulated results are compared with labelled electrical parameters which shows close proximity to the labelled parameter at particular values of series and shunt resistance. This paper also presents the effect of variation in series resistance (Rs) and shunt resistance (Rsh) on the performance of the SPV module under normal operating condition. The dependency of SPV electrical parameters (Imax, Vmax, Pmax, FF, η) with the variation of series resistance (Rs) and shunt resistance (Rsh) is simulated, and the effects are discussed in details

Internet of Things (IoT) based outdoor performance characterisation of solar photovoltaic module

Outdoor performance characterisation of the Solar Photovoltaic (SPV) module is essential to while designing and commissioning a new SPV power plant. The health of SPV plant is monitored using a conventional method which underutilises the workforce and resources used for Operation and Maintenance (O&M) of the SPV power plant. Outdoor performance characterisation of SPV module using reliable, compact, portable, and economical Current-Voltage (I-V) curve tracer having IoT capability and auto sweep capability is presented in this paper. The capacitive load method is used for I-V curve sweep, and the result is compared with the resistive load method. In this paper, the advantages of using a capacitive load method over resistive load method are observed and experimentally validated. The ease of using IoT feature makes this proposed I-V Curve Tracer (IVCT) device more reliable to trace Current-Voltage (I-V) curve and Power-Voltage (P-V) curve for outdoor performance characterisation of SPV module

A Review of Maximum Power Point Tracking Algorithms for Wind Energy Conversion Systems

Renewable energy resources are gaining a lot of popularity. Several researchers have worked on the tracking and extraction of energy from these sources. In the past few decades, among the available green energy resources, wind energy has been the most attractive option among the resources available. It is imperative to use the maximum power available in the wind to achieve the wind turbine (WT) operation at maximum power. The maximum power point tracking (MPPT) algorithms are a pioneer in this context. Many research papers are contributed in this domain which necessitates a thorough review while choosing an appropriate technique. This paper comprehensively focuses on reviewing different algorithms in the past and present for tracking maximum power point, and capturing maximized output power from the wind energy conversion system (WECS). In this paper, the algorithms are classified based on the direct and indirect power measurement, hybrid and smart algorithms for tracking maximum power point, and they are compared, considering the parameters like complexity, convergence speed, use of sensors, memory requirement, need for knowledge of system parameters, etc. The immense popularity of the different versions of perturb and observe (P&O) based algorithms due to their various features is evident from the literature. The review reveals that the hybrid maximum power point tracking algorithms can use the advantages of the conventional methods and eliminate their drawbacks